Given that the molecular weight of MgSO4.7H2O is 246.4564 and the molecular weight of 7 H20 molecules is 126.105, if one were to heat 246.4564 grams (8.7 oz) of the heptahydrate at 500F, one would get 120.3514 grams of the sulfate after heating.
If one were then to place the 120.3514 grams of sulfate in 252.210 grams of 100 proof vodka, should doing so result in having the original 246.4564 grams (8.7 oz) of heptahydrate sitting in 126.105 grams of pure ethanol? Or is there something that I'm not taking into account?
How quickly might the anhydrous form grab moisture back from the air?
Must it be used very quickly before it becomes ineffective for drying alcohol?
It would seem obvious that the water and ethanol would have different molecular weights. How might that throw off the above calculations?
Say you have 100ml of 50% (100 proof) vodka. Alcohol percentages are given by volume, so you have 50ml of alcohol and 50ml of water. Water has a density of approximately 1 gram per ml, so you have about 50 grams of water in the solution. Every gram of MgSO4 will hold ~.5g of water (according to your numbers, I did not confirm them), so THEORETICALLY you need about 100 grams of anhydrous MgSO4. In practice, use some extra MgSO4 to make sure that you got all the water as in all likelihood the MgSO4 won't be 100% anhydrous, and it's also quite possible that you have a bit more than 50ml water due to concentration by evaporation of the alcohol. That seems like a lot of MgSO4 to me. I would try to find more concentrated alcohol (everclear probably) if I were you.
Also, the MgSO4 will pick up water from the air fast enough that I would either dry it out in the oven shortly before you need it, or seal it in something that is as close to absolutely air-tight as you can get if you want to store it in its anhydrous state. The actual rate at which it adsorbs depends on a few things such as humidity, the surface area of the MgSO4 (how finely ground and spread out it is), and others.
Hope my math was all good there. I've been up for way too long right now.
I also wanted to address this:
I seen three layers two distinced and one not so. Gelatin material on top then acetone layer then water.
Acetone and water are fully miscible, meaning they mix together. Like adding alcohol to water. You don't get layers because alcohol and water are miscible. You wouldn't see a layer of acetone and then a layer of water, so I'm not sure what solvent you were using but it wasn't acetone. That or you were seeing a layer of something else, or thought you saw a layer where there was none. Just wanted to point that out. Now acetone is pretty non-toxic (and actually I believe it can be produced by your body in some circumstances), but I wouldn't be drinking it anyway. Actually that whole post confused me a little bit, so maybe I just understood you wrong. If that's the case, I'm sorry. I just mention this in the interest of harm reduction.
That reminds me of one other thing I have seen a lot of in all this discussion of defeating the OPs. A lot of people seem to worry about the safety of solvents used. Now that's a legitimate concern if you're planning to ingest the solvent, but if you dry it properly, use a well ventilated area, and have pure solvent, there shouldn't be any solvent (or contaminates within) entering your body.
Anyhow.... These new OxyContins really are a pain in the ass

! I hate them. I messed around with a few of the 20mg ones today and made a couple observations: Nothing ground.breaking, though, unfortunately.
I put a whole pill into several ml (enough to cover it) of diethyl ether. Let it sit for an hour or so and there was NO change at all. I pulled it out, blew on it to dry it for a couple seconds, and it looks exactly the same as when it went in. Have not yet tested if it's just the coating protecting it or if the inner part of the pill is impervious as well because I don't have much ether left. When I distill some more I will report back if I think of it.
Second thing I tried and observed was when I put a pill into a concentrated solution of NaOH. (I didn't take measurements of the weight or ml of water but the pH shows right around 14 with indicator paper. This pill has been sitting in the solution for about 3 hours now, and it doesn't seem to be doing anything either. It's not gelling up, not breaking down. Just stting there.
As I wrote this though I thought about it and decided to pull it out of the NaOH solution to examine it more closely.. I rinsed it off with some water and squeezed it between my fingernails and found that it seemed to crumble a little bit more easily than one that hadn't been soaked. It still gelled on contact with the water when I rinsed it off.
I don't know if that will be of any help to any of the research and testing going on there, but hey, data is data. Maybe the ether bit is useful. I wold bet that freebase oxycodone is is soluble in ether and apparently nothing else in the pill is.
When I have money to whip up a batch of chloroform, I will try that out as a solvent next. If anyone wants to try it out before me, chloroform is pretty easy to make. You just need bleach and ethanol (preferably everclear). You can also use acetone instead of the alcohol. Google chloroform synthesis and check it out.
Oh, one more thing before I wrap up this needlessly long post. I really wish we could leave the microwave thing alone in this thread unless somebody finds a big improvement to it. I've tried the microwave technique many times, in many different ways, on 3 different microwaves... I use my opiaites intravenously and I've got to say I'm not impressed at all. There is still a good amount of gel in solution and even after multiple filterings (granted, I only have cotton at my disposal), it just doesn't look like something anyone should be putting into their circulatory system. Not to mention it just doesn't seem to extract a whole lot of the oxycodone anyway.